Are the 10 Gurus considered to be God in Sikh belief?

Respected Brother/Sister,
Waheguru ji ka Khalsa, Waheguru ji ki Fateh!

In reply to your question, the undersigned wants to say that the First Guru Person, Guru Nanak Sahib had made it very clear, in his discussion with Yogis, that his Guru was Shabad when he said Shabad Guru Surat Dhun Chela (ਸਬਦ ਗੁਰੂ ਸੁਰਤਿ ਧੁਨਿ ਚੇਲਾ).

Therefore, Shabad was the Guru of Sikhs from the very beginning. Each of the Guru Persons, who were spiritually one with Akalpurakh, came with a mission from Him, and after fulfillment of the same, were replaced with the next Guru Person.

In Guru Granth Sahib it is recorded that though the bodies of Guru Persons changed but the Jot (flame or light) remained the same:-

ਲਹਣੇ ਦੀ ਫੇਰਾਈਐ ਨਾਨਕਾ ਦੋਹੀ ਖਟੀਐ ॥ ਜੋਤਿ ਓਹਾ ਜੁਗਤਿ ਸਾਇ ਸਹਿ ਕਾਇਆ ਫੇਰਿ ਪਲਟੀਐ ॥ {ਪੰਨਾ 966}

ਅਰਥ: (ਜਦੋਂ ਗੁਰੂ ਨਾਨਕ ਦੇਵ ਜੀ ਨੇ ਗੁਰਿਆਈ ਦਾ ਤਿਲਕ ਬਾਬਾ ਲਹਣਾ ਜੀ ਨੂੰ ਦੇ ਦਿੱਤਾ, ਤਾਂ) ਗੁਰੂ ਨਾਨਕ ਸਾਹਿਬ ਦੀ ਵਡਿਆਈ ਦੀ ਧੁੰਮ ਦੀ ਬਰਕਤਿ ਨਾਲ, ਬਾਬਾ ਲਹਣਾ ਜੀ ਦੀ ਵਡਿਆਈ ਦੀ ਧੁੰਮ ਪੈ ਗਈ; ਕਿਉਂਕਿ, (ਬਾਬਾ ਲਹਣਾ ਜੀ ਦੇ ਅੰਦਰ) ਉਹੀ (ਗੁਰੂ ਨਾਨਕ ਸਾਹਿਬ ਵਾਲੀ) ਜੋਤਿ ਸੀ, ਜੀਵਨ ਦਾ ਢੰਗ ਭੀ ਉਹੀ (ਗੁਰੂ ਨਾਨਕ ਸਾਹਿਬ ਵਾਲਾ) ਸੀ, ਗੁਰੂ (ਨਾਨਕ ਦੇਵ ਜੀ) ਨੇ (ਕੇਵਲ ਸਰੀਰ ਹੀ) ਮੁੜ ਵਟਾਇਆ ਸੀ।

ਜੋਤ ਦੇ ਅਰਥ ਹਨ – ਪ੍ਰਕਾਸ਼, ਚਮਕ, ਤੇਜ ਤੇ ਜੋਤਿ ਦੇ ਅਰਥ ਹਨ – ਆਤਮਿਕ ਰੋਸ਼ਨੀ, ਰੂਹਾਨੀ ਰੋਸ਼ਨੀ ਤੇ ਜੁਗਤਿ ਦਾ ਅਰਥ ਹੈ ਜੀਵਨ ਦਾ ਢੰਗ।

Guru Granth Sahib is teaching us in the above Stanza that there is no difference between the Second Guru Person, Guru Angad Sahib and the First Guru Person, Guru Nanak Sahib, because spiritually both were one and their life style was also the same. This continued upto the Tenth Guru Person, Guru Gobind Singh Sahib.

Finally, Tenth Guru Person, Guru Gobind Singh Sahib, after completing his mission, closed, the lineage of living Guru Persons, and ordained Guru Granth Sahib, as ever living Guru of Sikhs.

Since Shabad and not the bodies of the Gurus, Bhagats and learned Sikhs, whose Baani is included in Guru Granth Sahib, is the Guru, therefore, the same spirituality is being taught by each one of them and there is no difference whatsoever.

Hope it helps. If you have any further questions, please do ask. If you find any deficiencies, please point out the same, for improvement in future.

Regards,
Your Brother